The quantum physics of photon scattering processes in atoms, atomic ions and simple molecules, are discussed in this unique approach. Focusing on this topic from a theoretical perspective, this volume fulfills a need for researchers and students in the field.

These volumes contain 365 of the 505 papers presented at the VUV-11 Conference, held at Rikkyo University, Tokyo, from August 27th to September 1st 1995. The papers are divided into three sections: atomic and molecular spectroscopy, solid state spectroscopy and instrumentation and technological applications. New aspects presented were both quantitative and qualitative improvements in fluorescence spectroscopy and magnetic circular dichroism measurements. The fluorescence data are complementary to those of photoemission in a sense but they appear to open up a new method to analyze the optical excitation and relaxation processes. The application of magnetic circular dichroism has proved to be useful not only in analyzing the electronic structures of magnetic materials but also in practical applications to material engineering as found in experiments combined with photoelectron microscopy. Excellent developments in applications are only found in the field of surface photochemistry, where the technique of etching using VUV light has been appreciably refined. Although the majority of distinctive scientific features in the VUV-11 Conference have been brought about by the application of synchrotron radiation, experiments using a different type of light source appear to have progressed steadily. This is evident in the studies of plasma radiation.

In the summer of 1972, I had the privilege and responsibility of organizing a Gordon Conference on the "High-Energy Spectroscopy of Solids." The Thursday evening session focused on future directions for high-energy spectroscopy. The possibilities associated with synchrotron radiation for future research became a central issue. I was asked to choose the members of the panel and chair the session. Although all five members of the panel went on to have distinguished careers using synchrotron radiation, at the time some of them were skeptical about the future role of synchrotron radiation sources in high-energy photon spectroscopy. The discussion became heated, and many members of the audience spoke, both pro and con. One member of the panel produced a detailed argument that synchrotron radiation would never rival standard X-ray tubes. We found out that there were estimates for properties of synchrotrons that differed by orders of magnitude from those of X-ray tubes. That much uncertainty was expressed at a meeting that took place less than twenty years ago. It is hard to believe that, even though at that time synchrotron radiation was already being used for photoemission studies of solids and surfaces and intershell excitations in solids, the potential impact and importance of this area was not fully realized even by the experts. Today synchrotron radiation is one of the primary tools for studying surfaces, and synchrotron radiation has affected many other areas of condensed-matter physics---even superconductivity.